Mills has move to Oldham this evening with them reporting that he has signed a two year deal with the option of a third year.
Manager Lee Johnson said: "It's a great signing. He's young, hungry and got a lot of potential. We'll give him an identity and a bit of love and I feel he can be a really good player for us."
The deal brings to an end to his time at Burnley that has hardly been successful since he arrived from Reading ahead of the 2012/13 season on a season long loan with a guaranteed two years to follow.